Electricity is the word we use to describe effects caused by the flow of electric charge. The movement of electrical charge generates energy. Electrical energy can be used in a wide variety of applications such as movement, heat, light, communications and computation.

Robotics Application

In FIRST robotics, electricity is the main source of energy for all the robot does. Stored electrical energy is drawn out of a battery and used both to power motion and for the electronics in the computer which controls the robot. The transfer of energy from the battery to the robots various parts is done through electrical circuits. Safety is very important when working with electricity as electric shock can hurt and at higher voltages can kill.

A typical electrical circuit (see diagrams) might include:

  1. Power source: a battery or generator
  2. Wire: connects the parts together and provides a path for the current.
  3. Switch: a device that either stops and starts the current or changes which circuit the current goes through.
  4. Resistors: to lessen the flow of electricity. (various kinds)
  5. Load: This is the object that does an action, it could be a lightbulb, a motor, a pneumatic valve or a computer. There can be one or more loads in a circuit.

Example of a very simple electrical circuit

Drawings of electrical circuits are called schematic diagrams and can be used to build, understand, repair or alter circuits. They are drawn using special symbols which represent the objects, like a map of the circuit.

Example of schematic for circuit shown

click here to see more about schematic symbols:
Open Book Project – Lessons in Schematic Circuits
Thinkquest – Electric Circuit symbols
Educypedia – Technical databank


Amp or Ampere
A unit of measurement of electrical current
A device which uses chemicals and metal plates to create an electrical charge. This allows the energy to be used upon demand.
The path that electric current follows, most often in a loop or circle. Usually begins and ends at the power source. May be made up of many electrical elements.
How well something passes electrical charge. Different materials will conduct better or worse.
The movement or flow of electrically charged particles.
Objects that make use of the controlled motion of electrons. Used largely in computers and other control devices.
A wire or other conductor that provides a path for unwanted electricity to leave a circuit safely. This is a safety feature which helps prevent overload to a circuit which can cause damage.
Non-conductive material used to prevent contact with conductive material. One example is the plastic coating on many wires.
A unit of measurement of electrical resistance.
How much an object or substance resists or impedes the flow of an electrical current. Similar in concept to how friction slows down mechanical motion, resistance ‘slows’ electrical current.
Schematic diagram
A picture made of symbols that shows an electrical circuit or system.
Short circuit
When electricity is diverted to an easier pathway that bypasses part of the circuit. This problem happens when a conductive material makes unwanted contact with part of the circuit.
A unit of measurement of electrical force.
A unit of measurement of the rate of energy use.

Electrical Activities

If you wish to experiment with electrical circuits you can download these instruction sheets:

Simple circuit
Build-your-own Flashlight
“Don’t Eat Pete!” Electrical game